Anticancer Drug Discovery Based on Plant Biodiversity (Abstract)

Contrary to the mainstream compound library screening established by pharmaceutical companies, our studies focus on natural products for discovery of potent biologically active agents from thousands of plant extracts. The advantage of screening natural products is that the chemical space covered by natural products is much more diversified, which is considered as a key to successful drug discovery research. By participating in several multi-disciplinary cooperative programs, we had an opportunity to access a sample library containing more than 6,000 plant extracts. Through evaluation of cell killing activity of the sample library against a panel of human cancer cell lines, we have already discovered 370 active plant leads, including 44 with an IC50 value of less than 1 μg/ml, 45 with an IC50 value in the range of 1-3 μg/ml, 55 with an IC50 value in the range of 3-5 μg/ml and 138 with an IC50 value in the range of 10-20 μg/ml. The plant extracts were derived from 229 plant species in 88 families, which were collected from Southeastern Asia countries including China, Vietnam and Laos. Bioassayguided fractionation of several prioritized active plant extracts led to the isolation and identification of a series of potent anticancer compounds. Among these active compounds, several have demonstrated potent anticancer activity both in in vitro and in vivo studies.